Head injuries can be very severe when high velocity objects impact with the head. This is true in many sports, such as golf and baseball. Rigid, impact-resistant baseball safety caps are known but they do not protect against biting insects and they lack in air ventilation and in esthetic value. Known golf caps made of fabric with different patterns and colors have an esthetic value, are useful for thermally insulating the wearer's head, are air permeable to allow head ventilation and provide a barrier against insects. However they cannot resist an impact.
U.S. Pat. No. 3,315,273 issued Apr. 25, 1967 to E. C. Bullard and entitled "Safety cap" shows and describes a safety cap to be used by industrial and commercial workers. It comprises a rigid, impact-resistant shell having a front visor and a cloth cover adapted to fully cover the shell; the shell has no ventilation openings and the cloth cover is snapped onto the outer surface of the rigid shell by means of studs outwardly protruding from the shell rim. The purpose of the cloth cover is to prevent electrical static charge, adjustment of the cap to different head sizes is accomplished by forming the shell into a plurality of segments obtained by vertical slots in the shell. These slots cannot provide air ventilation since they are covered by an inside padding made of sponge rubber and not air permeable.